Rockwell Automation 1771-IXE/D Thermocouple/Millivolt Input Module User Manual - Manual (Page 52)

7–2 Troubleshooting
Publication 1771Ć6.5.130 Ć May 1999
Table 7.A shows LED indications and probable causes and
recommended actions to correct common faults.
Table 7.A
Troubleshooting Chart for Thermocouple/Millivolt Input
Module (1771-IXE/D)
Indication Probable Cause Recommended Action
Both LEDs are OFF No power to module
Possible short on the module
LED driver failure
Check power to I/O chassis. Recycle as
necessary.
Replace module.
Red FLT LED ON and
Green RUN LED is ON
Microprocessor, oscillator or EPROM failure Replace module.
Red FLT LED ON If immediately after power-up, indicates RAM or
EPROM failure. 1
Replace module.
If during operation, indicates possible
microprocessor or backplane interface failure. 1
Replace module.
Green RUN LED is flashing Power-up diagnostics successfully completed. Normal operation.
If LED continues to flash, and write block transfers
(BTW) cannot be accomplished, you have a
possible interface failure.
Replace module.
1 When red LED is on, the watchdog timer has timed out and backplane communications are terminated. Your user program should
monitor communication.
Status Reported in Word 1
Design your program to monitor status bits in the lower byte of word
1, and to take appropriate action depending on your application
requirements. You may also want to monitor these bits while
troubleshooting with your industrial terminal. The module sets a bit
(1) to indicate it has detected one or more of the following conditions
as shown in Table 7.B.
Table 7.B
Status Reported in Word 1
Word Bit Explanation
1 00 Module is powered but has not received its first (configuration) block transfer.
The green LED is flashing.
01 One or more inputs are out of the range for which you configured the module.
02 Module updated its inputs before the processor read them. The RTSinterval
timed out before the processor read the data.
03 Not used
Word 1
(cont)
04 The module's ambient temperature is below 0 o C. Temperature readings will
be inaccurate.
05 The module's ambient temperature is above 60 o C. Temperature readings will
be inaccurate.
Troubleshooting with the
Indicators
Status Reported by the
Module